CONTEXT: An analysis of paid malpractice claims may provide insight into the prevalence and seriousness of adverse medical events in the outpatient setting.OBJECTIVE: To report and compare the number, magnitude, and type of paid malpractice claims for events in inpatient and outpatient settings.DESIGN AND SETTING: Retrospective analysis of malpractice claims paid on behalf of physicians in outpatient and inpatient settings using data from the National Practitioner Data Bank from 2005 through 2009. We evaluated trends in claims paid by setting, characteristics of paid claims, and factors associated with payment amount.MAIN OUTCOME MEASURES: Number of paid claims, mean and median payment amounts, types of errors, and outcomes of errors.RESULTS: In 2009, there were 10,739 malpractice claims paid on behalf of physicians. Of these paid claims, 4910 (47.6%; 95% confidence interval [CI], 46.6%-48.5%) were for events in the inpatient setting, 4448 (43.1%; 95% CI, 42.1%-44.0%) were for events in the outpatient setting, and 966 (9.4%; 95% CI, 8.8%-9.9%) involved events in both settings. The proportion of payments for events in the outpatient setting increased by a small but statistically significant amount, from 41.7% (95% CI, 40.9%-42.6%) in 2005 to 43.1% (95% CI, 42.1%-44.0%) in 2009 (P < .001 for trend across years). In the outpatient setting, the most common reason for a paid claim was diagnostic (45.9%; 95% CI, 44.4%-47.4%), whereas in the inpatient setting the most common reason was surgical (34.1%; 95% CI, 32.8%-35.4%). Major injury and death were the 2 most common outcomes in both settings. Mean payment amount for events in the inpatient setting was significantly higher than in the outpatient setting ($362,965; 95% CI, $348,192-$377,738 vs $290,111; 95% CI, $278,289-$301,934; P < .001).CONCLUSION: In 2009, the number of paid malpractice claims reported to the National Practitioner Data Bank for events in the outpatient setting was similar to the number in the inpatient setting.